The effect of context and drivers’ age on highway traffic signs comprehension

Background: Comprehension of traffic signs is crucial to safety. Objectives: To test the effects of the presentation condition (with or without driving context) on symbolic based road signs comprehension and comprehension time for young and older drivers. Method: 50 young drivers and 50 older drivers were presented with images of 28 Israeli road signs, both without context (with a white background) and in context (with the driving surrounding). Data were collected on the accuracy of signs meaning and on the time it took the participants to provide the meaning. Results: Younger drivers performed significantly better than older drivers on both accuracy and response time (RT). Older drivers’ average RT was approximately twice as long as younger drivers’ RT. However, the presentation mode (with or without context) did not affect sign comprehension of either group, but the presence of the context did increase the time it took the drivers to comprehend the sign’s meaning. In addition, correct response time was similar to opposite to sign’s meaning response time. Implications: Older drivers, can benefit from retraining in sign comprehension of current signage. The training should involve signs in their natural road environment to reduce comprehension time while actually driving. Moreover, signs that were understood as having an opposite meaning should be redesigned or be accompanied by text.     

A simulator study of factors influencing drivers’ behavior at traffic lights

Drivers’ reactions to changing traffic lights have an impact on safety at intersections. We examined the influence of transient factors – more specifically time pressure and social context, both conducive to traffic-light violation – on behavior behind the wheel when a traffic light changes. We carried out an experiment on a driving simulator. The participants were 94 car drivers (53 males) with a mean age of 21.7 years. They drove under time pressure vs. no time pressure. At several intersections the participants were alone (no other drivers present), whereas at several other intersections they were behind a line-up of vehicles, the last of which ran the yellow light (other drivers present). As expected, time pressure and social context (presence of other drivers) increased participants’ risky behaviors while approaching, and going through traffic lights, as well as undesirable rapid accelerations when the signal changes to green. The effect of time pressure on yellow-light running was not mediated by approach speed, which showed that participants in a hurry were likely to run lights intentionally. The results are interpreted in view of proposing effective measures for reducing yellow-light running and rapid accelerations at traffic lights.     

Socio-economic and driving experience factors affecting drivers’ perceptions of traffic crash risk

Drivers are estimated to contribute an overwhelming proportion to the burden of traffic crashes, as factors that increase crash risk are frequently due to unsafe driving behaviours. The relationship between risk perceptions and people’s risky driving behaviours is still not well understood. This paper aims to further analyse the potential effect of risky driving behaviours on drivers’ perceptions of crash risk and differences in perceptions among drivers.Crash risk perceptions in an inter-city, two-way road context of 492 drivers were measured by using a Stated Preference (SP) ranking survey. Rank-ordered logit models were used to evaluate the impact on risk perception of five unsafe driving behaviours and to identify differences in drivers’ risk perceptions. The five unsafe driving behaviours considered in the analysis were respectively related to whether or not the driver follows the speed limits, the rules of passing another car and the safe distance, whether or not the driver is distracted, and whether or not she/he is driving under optimal personal conditions.All risky driving behaviours showed a significant potential effect (p < 0.001) on crash risk perceptions, and model’s results allowed to differentiate more important from less important unsafe driving behaviours based on their weight on perceived crash risk. Additionally, this paper further analyses the potential differences in risk perception of these traffic violations between drivers of different characteristics, such as driving experience, household size, income and gender.The SP technique could be applied to further analyse differences in perceptions of risky driving behaviours among drivers. Future research should consider the potential effect of driving skill on perceptions of risky driving behaviours.     

Effect of motorcycle lighting configurations on drivers’ perceptions of closing during nighttime driving

ObjectiveThe aims were to better understand how drivers perceive an approaching set of motorcycle headlights during nighttime driving and to determine whether alternative motorcycle headlight configurations improve drivers’ perceptual judgments of closing for an oncoming motorcycle.BackgroundMotorcyclists account for a disproportionate number of roadway fatalities, especially at night. One potential cause of this is drivers’ misjudgments of a motorcycle’s approach.MethodThe first experiment examined whether drivers were more sensitive to horizontal or vertical optical expansion and whether drivers could integrate these two dimensions to achieve a lower looming threshold. A second experiment built on these results to test whether alternative headlight configurations that maximized size were better than other motorcycle headlight configurations and a car’s headlights. In both experiments, participants were instructed to press a button to indicate when they first perceived an oncoming vehicle to be closing under nighttime driving conditions.ResultsHeadlight orientation did not affect when drivers perceived closing, and drivers were not able to integrate optical expansion from multiple dimensions in a way that achieves a lower looming threshold. However, the alternative motorcycle headlight configurations that accentuated the full extent of a motorcycle’s size resulted in drivers perceiving closing sooner than other motorcycle headlight configurations but not sooner than a car.ConclusionDrivers perceive closing sooner for larger headlight configurations except when the headlight configurations are relatively small, in which case the effect of headlight size is attenuated.ApplicationDrivers’ perceptual judgments of motorcycles may improve when motorcycles have headlights that span its full height.     

Factors influencing drivers’ reading and comprehension of on-board traffic messages

IntroductionWhen variable message signs (VMS) or on-board traffic information systems are used, it is essential that while driving, motorists read and understand the information as soon as possible in order to make appropriate decisions to increase road safety and/or facilitate traffic flow. Thus, it is important to investigate the factors that may increase fast reading and comprehension of on-board traffic information.ObjectivesWe examined the influence of the type of message (warnings vs. recommendations), location of the pictogram (top or bottom of the text), type of display device (IPhone, Blackberry, or Tablet) and its position (horizontal or vertical) on drivers’ fast reading and comprehension of on-board messages provided via in-vehicle system. Moreover, we were interested in drivers’ acceptability of in-vehicle system.MethodForty-nine drivers (M_Men = 32, 19–65 years) participated to a reading and comprehension task while travelling on a desktop driving simulator. Participants were exposed to two series of 11 traffic messages displayed on one of the three devices. Reading and comprehension times were measured (= milliseconds) for each message. At the end, they had to fill in a questionnaire on their beliefs about on-board traffic messages and in-vehicle system.ResultsDrivers expressed a positive attitude toward on-board traffic messages and in-vehicle system. Reading and comprehension times were of approximately 4 seconds and were longer for warnings as compared to recommendations. The pictogram placed at the top of the text, the tablet and the vertical display device facilitated fast reading and comprehension.     

The impact of different styles of traffic safety advertisement on young drivers’ explicit and implicit self-enhancement biases

This study examined the immediate psychological impact of positive and negatively framed driving advertisements on (a) deliberative and consciously reported (explicit) and (b) automatic non-conscious (implicit) self-enhancement biases in driving ability and caution (N = 150). Positively framed driving advertisements (those that showed actors modeling safe alternatives to dangerous driving) were most effective at reducing self-enhancement biases in driving ability. This effect was, however, limited to consciously accessible deliberative self-enhancement biases. Exposure to driving advertisements (either positively or negatively framed) did not significantly alter implicit, automatic self-enhancement biases (measured using a computerized reaction-time task). These findings emphasize that positively framed messages are more effective than negatively framed messages at influencing important psychological processes underlying driving behaviour, although such effects are limited, at least in their immediacy, to deliberative fast-learning (or propositional) processes. The implications of these findings for understanding the effects of driving advertisements on the different slow-learning and fast-learning social-cognitive processes underlying self-enhancement biases in young drivers’ self-perceptions, and hence driver behaviour, are discussed.     

The factors of female taxi drivers’ speeding offenses in Taiwan

Females choosing taxi driving as a career is rare, therefore, investigating such samples is often difficult. Speeding is one of the most common driving violations, however, there has been no research looking into female taxi drivers’ speeding issue. This study explores the factors of female taxi drivers’ speeding offenses in Taiwan. Data is based on a national survey and includes 235 professional female taxi drivers. The results indicate that female taxi drivers work approximately 27.37 days per month, at a mean of 9.76 h per day. Of the female taxi drivers represented in this study, 22.8% reported at least one speeding offense over a one-year period. The results of a logistic regression model reveal that the determinant factors associated with female taxi drivers’ speeding offenses are significantly related to age, educational level and mileage driven. However, job experience, business operating style, and vehicle engine size are not associated with committing speeding offenses. Practical implications for traffic safety of female taxi drivers are also discussed.     

Toward a greater understanding of Colombian professional truck drivers’ safety performance

In this investigation involving 227 lone professional truck drivers from a national transportation company in a low and moderate-income country (LMIC), Colombia, a multidimensional model of drivers’ safety performance and expectations concerning how safety performance dimensions would predict hard braking were evaluated. The results supported a multidimensional conceptualization of professional truck drivers’ safety performance, with factors aligned with confirmed general safety performance factors and occupation-specific factors. Furthermore, results supported the expectation that the dimensions associated with communicating safety information and complying with laws and regulations would predict hard braking over and above less conceptually relevant safety performance dimensions such as using personal protective equipment and preparing to drive, safety climate, and region of operation. Notably, a dimension of safety performance expected to promote workplace safety, the communication of health and safety information, was associated with increased hard braking. We discuss the implications of a multidimensional conceptualization and measure of safety performance for studying workplace safety for professional truck drivers in Colombian organizations and beyond.     

Analysis of the factors affecting drivers’ queue-jumping behaviors in China

In China, drivers’ queue-jumping behaviors are very common. To explore the factors affecting drivers’ queue-jumping, first, a driving attitude scale, a risk perception scale and a queue-jumping behavior scale were designed, and an existing Type A behavior pattern scale and a driver skill scale were also introduced. Second, these scales were used to collect empirical data, and 202 valid samples were obtained. Third, the reliability and validity of the developed scales were verified, and a structural equation model of drivers’ queue-jumping behaviors was established to explore the interrelationships among the Type A personality trait, cognitions (including attitudes and risk perception), driver skills (including driving skill and safety motivation) and queue-jumping behaviors. The results showed that drivers’ cognitions significantly affected their queue-jumping behaviors; specifically, drivers’ attitudes toward queue-jumping and traffic violations positively correlated with their queue-jumping behaviors (β = 0.323, t = 3.470; β = 0.277, t = 3.072), while drivers’ risk perception toward queue-jumping negatively correlated with their queue-jumping behaviors (β = −0.297, t = −3.889). Drivers’ driving skill and safety motivation also significantly affected their queue-jumping behaviors (β = 0.198, t = 2.385; β = −0.355, t = −4.101). Although Type A personality trait had no significant effects on drivers’ queue-jumping behaviors, it had significant effects on drivers’ attitudes toward queue-jumping and traffic violations (β = 0.336, t = 4.720; β = 0.215, t = 2.873) and their risk perceptions toward queue-jumping (β = −0.232, t = −3.279). In other words, the Type A personality trait can indirectly affect drivers’ queue-jumping behaviors through drivers’ attitudes and risk perceptions toward queue-jumping. The results provided offer traffic administration departments a theoretical foundation for governing this behavior.     

Impact of interface design on drivers’ behavior in partially automated cars: An on-road study

In partially automated vehicles, the driver and the automated system share control of the vehicle. Consequently, the driver may have to switch between driving and monitoring activities. This can critically impact the driver’s situational awareness. The human–machine interface (HMI) is responsible for efficient collaboration between driver and system. It must keep the driver informed about the status and capabilities of the automated system, so that he or she knows who or what is in charge of the driving. The present study was designed to compare the ability of two HMIs with different information displays to inform the driver about the system’s status and capabilities: a driving-centered HMI that displayed information in a multimodal way, with an exocentric representation of the road scene, and a vehicle-centered HMI that displayed information in a more traditional visual way. The impact of these HMIs on drivers was compared in an on-road study. Drivers’ eye movements and response times for questions asked while driving were measured. Their verbalizations during the test were also transcribed and coded. Results revealed shorter response times for questions on speed with the exocentric and multimodal HMI. The duration and number of fixations on the speedometer were also greater with the driving-centered HMI. The exocentric and multimodal HMI helped drivers understand the functioning of the system, but was more visually distracting than the traditional HMI. Both HMIs caused mode confusions. The use of a multimodal HMI can be beneficial and should be prioritized by designers. The use of auditory feedback to provide information about the level of automation needs to be explored in longitudinal studies.     

Effects of position of speed limit signs and the presence of speed camera on Malaysian drivers’ speed choice: An eye-tracking study

Speeding is one of the most common driving violations in the world including in Malaysia. Reducing speed-related fatalities is one of Malaysia’s strategies to improve road safety. The current study aimed to investigate the effect of speed limit sign positioning and the presence of speed camera on drivers’ judgments about the appropriate speed to drive and their associated eye movements. Twenty participants took part in the study, and thirty two images of roads with a range of actual speed limits were presented. In each picture the displayed speed limit was edited to 30% lower than what participants think is appropriate on average. Speed limit signs were either presented on the road or on the speed limit sign boards at the road sides, and a speed camera sign was either present or not. Drivers judged a lower appropriate speed to drive when the camera sign was present than absent, while there was a wider spread of differences between judged and displayed speed when the speed limit sign was presented on the board than on the road. Drivers were quicker in fixating and looked more at the general area in which the speed limit sign appeared. Therefore drivers’ visual attention across scenes may be manipulated by the sign positions. These low-cost interventions could be useful in managing speed choice in Malaysia.     

An eye-tracking study of the effects of dimensions of speed limit traffic signs on a mountain highway on driverś perception

Signs control and regulate traffic, anticipating potential dangers, prescribing correct behaviors, and disambiguating likely conflicts in priority. In Brazil, traffic accidents on highways located in mountain rural areas are mainly related to the design of roads and speeding, rather than to the impact of traffic flow. Since drivers highly depend on their visual perceptions for adopting driving behaviors, this study analyzes driver perception during a trip and the response of this parameter to changes in the diameter of vertical speed limit signs in a driver simulator equipped with an eye-tracking system. The objective was to investigate whether an increase in the plate size would enhance driver perception and influence drivers’ compliance with speed limits. Fifty-five volunteers were asked to drive twice on a 10-km mountain route, after which one of the diameters, namely 75, 100, 120, and 150 cm, used according to several Brazilian and American standards, was randomly chosen. The results showed the size of the traffic signs did not affect dependent variables number of fixations, percentage of perceived signals, time of observation, perception distance, and non-compliance with the speed limit. The most significant result was the relationship between speed variability and guided round, since the driver’s performance was improved with the distance along the studied stretch. The outcomes can be useful for the development of strategies that manage speeding on roads by improving and implementing low-cost interventions in low-income countries.     

The effect of drivers’ eye contact on pedestrians’ perceived safety

Many fatal accidents that involve pedestrians occur at road crossings, and are attributed to a breakdown of communication between pedestrians and drivers. Thus, it is important to investigate how forms of communication in traffic, such as eye contact, influence crossing decisions. Thus far, there is little information about the effect of drivers’ eye contact on pedestrians’ perceived safety to cross the road. Existing studies treat eye contact as immutable, i.e., it is either present or absent in the whole interaction, an approach that overlooks the effect of the timing of eye contact. We present an online crowdsourced study that addresses this research gap. 1835 participants viewed 13 videos of an approaching car twice, in random order, and held a key whenever they felt safe to cross. The videos differed in terms of whether the car yielded or not, whether the car driver made eye contact or not, and the times when the driver made eye contact. Participants also answered questions about their perceived intuitiveness of the driver’s eye contact behavior. The results showed that eye contact made people feel considerably safer to cross compared to no eye contact (an increase in keypress percentage from 31% to 50% was observed). In addition, the initiation and termination of eye contact affected perceived safety to cross more strongly than continuous eye contact and a lack of it, respectively. The car’s motion, however, was a more dominant factor. Additionally, the driver’s eye contact when the car braked was considered intuitive, and when it drove off, counterintuitive. In summary, this study demonstrates for the first time how drivers’ eye contact affects pedestrians’ perceived safety as a function of time in a dynamic scenario and questions the notion in recent literature that eye contact in road interactions is dispensable. These findings may be of interest in the development of automated vehicles (AVs), where the driver of the AV might not always be paying attention to the environment.     

Effect of auditory in-vehicle warning information on drivers’ brake response time to red-light running vehicles during collision avoidance

There is usually a high red-light running (RLR) collision rate at signalized intersections because of the unpredictability of dangerous RLR vehicles traversing intersections illegally. The RLR collision warning systems can help drivers be aware of the red-light running (RLR) vehicles and take collision avoidance actions timely. The objective of this paper is to evaluate the effects of auditory warning information on brake response time (RT) to red-light running vehicles during the collision avoidance process based on a driving simulator experiment. Warning status (e.g., warning vs. no warning), warning lead time (3 s vs. 5 s) and warning content (directional information vs. undirectional information) were considered to examine the effectiveness of the RLR collision warning system under different conditions. The experiment results showed that the auditory warning information can effectively reduce brake RT and collision occurrence rate and RT is the most influential variable on the collision occurrence. Although early warning is more effective than late warning in reducing brake RT and collision rate, the late warning can still lower the collision rate by 37%. However, the directional warning information did not have apparent advantages over the undirectional warning information. The findings of this study are helpful for the designers of RLR collision warning systems to enhance the effectiveness of the systems’ application on traffic safety.     

Models as signs: extending Kralemann and Lattman’s proposal on modeling models within Peirce’s theory of signs

Synthese - In recent decades, philosophers of science have devoted considerable efforts to understand what models represent. One popular position is that models represent fictional situations....     

A comparison of experienced and novice drivers’ rear-end collision avoidance maneuvers under urgent decelerating events

A leading vehicle’s sudden deceleration can lead to a rear-end collision. Due to a lack of driving experience, novice drivers have a greater tendency to be involved in these accidents. Most previous studies have examined driver response time and braking behaviors, but few researchers have focused on what experienced and novice drivers did after their feet touched the braking pedal and their hands turned the steering wheel. These braking and steering parameters are essential in understanding driver avoidance behavior during emergencies. We programmed rear-end crash risk scenarios to examine experienced and novice drivers’ behaviors thoroughly using a driving simulator. Twenty experienced and twenty five novice subjects participated in our experiments, and their braking and steering maneuvers were recorded when leading vehicles ran at 60 km/h, 80 km/h and 100 km/h. The results showed that the two groups of subjects tended to execute two kinds of maneuvers to avoid crashes: braking only (novice 33%, experienced 19%) and the combination of braking with steering (novice 22%, experienced 26%). When the novice drivers executed braking with steering, their response time and steering duration were significantly longer than those of the experienced drivers who executed braking with steering. As the speed increased, the novice drivers’ response time, maximum braking force and maximum steering angle were significantly affected. These results showed that novice drivers should brake only when the leading vehicle suddenly decelerates. The experienced drivers executed steadier maneuvers. Their risk perception time was shorter, and their maximum braking force and the maximum steering angles were smaller. The response time, braking intensity and steering wheel angle should be considered when developing rear-end collision warning systems.     

Situational specificity of trait influences on drivers’ evaluations and driving behaviour

This study explored the influence of anger and anxiety traits on driver evaluations and behaviour during a simulated drive. Forty-eight licensed drivers completed identical simulated driving tasks during which they rated levels of current anger, calmness and frustration or levels of danger, calmness and difficulty. Anxiety-prone drivers made higher difficultly evaluations and generally drove more cautiously. Anger-prone drivers gave higher ratings of anger and frustration, but their evaluations and anger tendencies were unrelated to their general driving behaviours. When driving behaviours in high and low anger-provoking situations were contrasted, in low anger-provoking situations, drivers higher in trait anger reported more anger and frustration and also drove faster and with more sideward movement. When driving situations were considered separately, although not overall, behaviour and evaluations were related: when forced to move sideward, drivers reported more frustration; when forced to drive more slowly, they reported more anger, and subsequently increased acceleration, throttle pressure and steering wheel use. These relationships were not moderated by trait anger. Irrespective of trait anger, drivers become angry when impeded, or in other anger-provoking situations, only drivers with high trait anger become angry and behaved aggressively in circumstances most would not consider provocative.     

An examination of the factors that influence drivers’ willingness to use hand-held mobile phones

Hand-held mobile phone use while driving is illegal throughout Australia yet many drivers persist with this behaviour. This study aims to understand the internal, driver-related and external, situational-related factors influencing drivers’ willingness to use a hand-held mobile phone while driving. Sampling 160 university students, this study utilised the Theory of Planned Behaviour (TPB) to examine a range of belief-based constructs. Additionally, drivers’ personality traits of neuroticism and extroversion were measured with the Neuroticism Extroversion Openness-Five Factor Inventory (NEO-FFI). In relation to the external, situational-related factors, four different driving-related scenarios, which were intended to evoke differing levels of drivers’ reported stress, were devised for the study and manipulated drivers’ time urgency (low versus high) and passenger presence (alone versus with friends). In these scenarios, drivers’ willingness to use a mobile phone in general was measured. Hierarchical regression analyses across the four different driving scenarios found that, overall, the TPB components significantly accounted for drivers’ willingness to use a mobile phone above and beyond the demographic variables. Subjective norms, however, was only a significant predictor of drivers’ willingness in situations where the drivers were driving alone. Generally, neuroticism and extroversion did not significantly predict drivers’ willingness above and beyond the TPB and demographic variables. Overall, the findings broaden our understanding of the internal and external factors influencing drivers’ willingness to use a hand-held mobile phone while driving despite the illegality of this behaviour. The findings may have important practical implications in terms of better informing road safety campaigns targeting drivers’ mobile phone use which, in turn, may contribute to a reduction in the extent that mobile phone use contributes to road crashes.     

Real-time detection of drivers’ texting and eating behavior based on vehicle dynamics

With rapid advancement in cellphones and intelligent in-vehicle technologies along with driver’s inclination to multitasking, crashes due to distracted driving had become a growing safety concern in our road network. Some previous studies attempted to detect distracted driving behaviors in real-time to mitigate their adverse consequences. However, these studies mainly focused on detecting either visual or cognitive distractions only, while most of the real-life distracting tasks involve driver’s visual, cognitive, and physical workload, simultaneously. Additionally, previous studies frequently used eye, head, or face tracking data, although current vehicles are not commonly equipped with technologies to acquire such data. Also those data are comparatively difficult to acquire in real-time during traffic monitoring operations. To address the above issues, this study focused on developing algorithms for detecting distraction tasks that involve simultaneous visual, cognitive, and physical workload using only vehicle dynamics data. Specifically, algorithms were developed to detect driving behaviors under two distraction tasks – texting and eating. Experiment was designed to include the two distracted driving scenarios and a control with multiple runs for each. A medium fidelity driving simulator was used for acquiring vehicle dynamics data for each scenario and each run. Several data mining techniques were explored in this study to investigate their performance in detecting distraction. Among them, the performance of two linear (linear discriminant analysis and logistic regression) and two nonlinear models (support vector machines and random forests) is reported in this article. Random forests algorithms had the best performance, which detected texting and eating distraction with an accuracy of 85.38% and 81.26%, respectively. This study may provide useful guidance to successful development and implementation of distracted driver detection algorithms in connected vehicle environment, as well as to auto manufacturers interested in integrating distraction detection systems in their vehicles.     

Effect of blank samples on absolute odor threshold determinations’

Absolute odor thresholds for methyl isobutyl ketone were estimated under five conditions: odor sample-to-air blank ratios of 1:2, 1:1, 2:1, 4:1, and 9:1. Each of the five ratios was presented in two replicated balanced Latin square sequences to five adult human Ss. The results showed that significantly lower estimates of the threshold were obtained when the ratio of odor samples to air blanks was 1:1. These results are discussed in terms of possible adaptation effects, maintenance of an internal frame of reference as a basis for decisions, and response matching to pay-off expectancy.